OS X Server: How to require authenticated binding between server and clients

This setting only affects OS X clients binding to OS X Server. If it is enabled, clients will be prompted for a directory administrator password when binding to the server. This setting does not control or limit any other access the LDAP database on the server.

You can set this by using the slapconfig Terminal command on the server.

To require authentication when a client binds to the server, use this Terminal command:

sudo slapconfig -setmacosxodpolicy -binding required

To allow authenticated binding, but make it optional (the default setting), use this Terminal command: